diff --git a/web_view.py b/web_view.py
index 3eb3049..5e1e507 100755
--- a/web_view.py
+++ b/web_view.py
@@ -146,6 +146,8 @@ def start_oauth() -> Response:
     flask.session["owner_key"] = fetch_response.get("oauth_token")
     flask.session["owner_secret"] = fetch_response.get("oauth_token_secret")
 
+    assert flask.session["owner_key"] and flask.session["owner_secret"]
+
     base_authorization_url = f"https://{wiki_hostname}/wiki/Special:OAuth/authorize"
     authorization_url = oauth.authorization_url(
         base_authorization_url, oauth_consumer_key=client_key
@@ -162,8 +164,8 @@ def oauth_callback() -> werkzeug.wrappers.response.Response:
     oauth = OAuth1Session(
         client_key,
         client_secret=client_secret,
-        resource_owner_key=flask.session["owner_key"],
-        resource_owner_secret=flask.session["owner_secret"],
+        resource_owner_key=flask.session.get("owner_key"),
+        resource_owner_secret=flask.session.get("owner_secret"),
     )
 
     oauth_response = oauth.parse_authorization_response(flask.request.url)
@@ -343,8 +345,8 @@ def api_hits() -> werkzeug.wrappers.response.Response:
 @app.route("/api/1/valid_hit")
 def api_valid_hit() -> werkzeug.wrappers.response.Response:
     """Return canidates for the given article title."""
-    link_from = flask.request.args.get("link_from")
-    link_to = flask.request.args.get("link_to")
+    link_from = flask.request.args["link_from"]
+    link_to = flask.request.args["link_to"]
 
     try:
         diff, replacement = get_diff(link_to, link_from, None)